tb42 with pertronix and flame thrower coil, miss under load

[martysgq]

i just fitted a pertronix ignitor to my gq tb42 patrol. fitted new plugs and gaped them to 1.0mm. currently using a gt40r coil and it all ran fine, no flat spots or miss.

i throught i would get a flame thrower 3.0ohm coil and fitted that. now it misses under load around the 2000rpm mark. just wondering what could cause this. do i need more spark gap or less.

also running an extended rotor button. all the lead test fine.
also since i fitted the flame thrower coil the tacho moves around more.

[BowTieGQ]

I had the exact same setup on my GQ and the exact same problems. It was the coil breaking down under load. It caused it to heat up and break down more, compounding the problem. It became way too hot to touch. Suprised it didn't go bang.

I took the car back to the importer and showed him the problem. Returned goods and got my money back.

Went Crane setup and it worked perfectly from day one and I never touched it again.

[danny40]

Sorry to change the subject a little but does the better coil make a notacable difference? So far I have done petronics, top gun leeds, extended rotor button and extractors with 2.5 system.

Cheers

[MyGQ]

i have heard of many ppl putting higher output coils onto petronix setups and having problems, in fact the last one who did this blew up the petronix setup.

i used a Crane cam fireball XR700 and a 40,000 volt output coil and never missed a beat. gave the car more power

and yes if you have a higher output coil and the ignition system to handle it (the standard point setup can't) it makes a big difference as you getting power spark into the engine to burn the fuel

[BadMav]

When I put the pertronics on mine, the same would happen when warmed up, it had the same miss (especially on gas) with the GT40 coil which oddly looked brand new. I threw an accell super coil on it (overkill I know but I stole it off my drag car) and it runs sweet now. One thing to remember though, and it says it in the instructions, if your coil is meant to run a ballast resistor normally, YOU MUST RUN IT with the pertronics as well. You'll find that's probably what the other guys didn't do and why theirs got fried. From memory, if the coil has less than 3.0 ohms resistance you have to run a ballast resistor.